1. Field of the Invention
The present invention relates to graders. More particularly, the present invention relates to an improved spreader/grader of the type pulled by a tractor, having a plurality of grader blades which are adjustable to multiple positions either manually or by other force, such as hydraulic or pneumatic power.
2. General Background of the Invention
The named inventor of the present invention is the patentee in U.S. Pat. No. 5,332,331, on a combination grader/spreader apparatus having a pair of substantially parallel sidewalls, spaced apart, and supporting at least two spreader/grader blades therebetween. There is disclosed a hydraulic or manual adjustment member connected to one end of each of the cutting blades, for allowing the one end to be movably adjusted along the length of the sidewalls, so that the blades may be moved from a position substantially perpendicular to the length of the sidewall, to a position angulated therefore, so as to provide a means to prevent material graded to accumulate along the length of the blades, but to slide along the angulated blade and be deposited outside the grader apparatus. The blades are fixed in their relation to the surface itself, and cannot rotate about an axis.
The shortcoming of the device disclosed in the '331 patent was the fact that only one end of the grader blades was allowed to move along an axis, while the second end of the blades were fixed. This was a drawback, in that the blades could not be aligned in different positions from one another. They always were working in parallel formation, again with only one end movable along the frame. The inventor has developed an improved spreader/grader system which operates to solve this problem and allows the multiple blades to be fixed either in parallel, or in opposite directions depending on the need of the operator.